The present invention relates to medical imaging/biopsy systems, and more particularly, to an enhanced system that employs x-ray imaging and targeted ultrasound imaging in a combinative, spatially correlatable manner that is particularly apt for breast imaging/biopsy procedures. The invention further relates to targeted ultrasound features that yield plural modalities of operation as well as improved biopsy capabilities and a user interface system for facilitating targeting of a medical instrument to an area of interest within a patient""s breast.
The benefits of early detection and tissue diagnosis of potential lesions and/or suspicious masses within the body is now well established. Indeed, as medical practice and managed care plans continue to evolve, the role of early detection and tissue diagnosis is ever-increasing. With such emphasis, both efficacy and efficiency are at a premium. Specifically, reduction of the time requirements of highly trained medical personnel, patient office visits and medical equipment costs (e.g., via use of multiple-purpose equipment) are primary objectives for procedures utilized in the early detection and tissue diagnosis of potential lesions and otherwise suspicious masses.
Of particular ongoing interest is the area of mammography and breast biopsy. Currently, it is common for patients to receive regular screening mammograms, wherein two x-ray images are generated for each breast in order to identify potential lesions or masses suspicious for malignancy. In the event of equivocal screening mammograms, further x-ray or ultrasound imaging/exams may be performed to obtain additional information. The obtainment of a diagnostic mammogram and/or an ultrasound exam requires another patient office visit and additional medical personnel time. For example, if the presence of a suspicious mass is confirmed, an ultrasound procedure may be performed in order to further characterize the mass. Specifically, a free-hand procedure can be performed in which a hand-held ultrasound probe is manipulated on the breast while viewing a display to obtain depth-profile information. As can be appreciated, location of a potential lesion/suspicious mass can be difficult, and the ultrasound images obtained are frequently difficult to mentally associate with the x-ray images. As such, the ability to utilize ultrasound technologists as opposed to experienced physician specialists to perform most breast ultrasound procedures is limited.
Should a breast lesion show signs of malignancy pursuant to diagnostic mammography or ultrasound, a breast biopsy is typically performed. Needle localized surgical biopsy means have recently been giving way to stereotactic x-ray biopsy with automated core needles and tissue removal systems. A patient is typically positioned prone (e.g., on a solid table) with the breast immobilized within a predetermined frame of reference (e.g., the breast passes through an opening in the table and is immobilized between opposing compression plates). Stereotactic X-ray images are then generated (e.g., via x-ray film or digital imaging) for review by medical personnel to identify a specific location of interest (e.g., corresponding with a potential lesion or suspicious mass) within the predetermined frame of reference. A puncture instrument, mounted in predetermined relation to the predetermined frame of reference, is then positioned/utilized to obtain a sample of tissue from the location of interest. Of note, current state-of-the-art breast biopsy systems include the MAMMOTEST(copyright), MAMMOVISION(copyright) and SENOSCAN(trademark) products offered by Fischer Imaging Corporation of Denver, Colo. Such systems are further described in U.S. Pat. Nos. 5,078,142, 5,240,011, 5,415,169, 5,526,394 and 5,735,264, hereby incorporated by reference in their entirety.
While breast lesions may typically be biopsied utilizing stereotactic x-ray imaging, only recently have technical improvements in ultrasound allowed certain lesions to be biopsied under ultrasound guidance (i.e., with hand-held ultrasound probe and/or biopsy means). In this regard, ultrasound may be preferred due to the lack of ionizing radiation and the established availability of real time imaging to reduce procedure time.
Recent developments in tissue removal systems have resulted in larger, heavier devices that are difficult for a physician to use in conjunction with free-hand ultrasound guidance. As an example, the MAMMOTOME(trademark) from Biopsys Medical, Inc. of Irvine, Calif. allows rapid removal of breast tissue through a small puncture hole in the breast. Due to the weight and size of the device, physicians are performing more stereotactic x-ray procedures with the MAMMOTOME(trademark) due to the solid support of the device by prone stereotactic tables.
In the event that analysis of tissue by histopathologic techniques indicates that a lesion or undesirable mass should be removed from a breast, the surgeon will typically review the various breast images previously obtained to develop a therapeutic surgical strategy, with the goal of removing the entire potential lesion and/or suspicious mass while achieving acceptable cosmetic results.
It is an object of the present invention to provide an enhanced imaging/biopsy system that can reduce trained medical personnel time requirements in diagnostic and biopsy procedures for tissue diagnosis. It is a related objective to provide such a system in a cost-effective manner; namely through the provision of a system having relatively expensive components that can be utilized for multiple medical procedures combinatively employed in a single system.
A further objective of the present invention is to provide an enhanced imaging/biopsy system for obtaining spatially correlated three-dimensional image information regarding a location of interest in the body, such system being apt for the obtainment of three-dimensional image information regarding a potential lesion or suspicious mass in a female patient""s breast. It is a further objective to provide such information in a manner allowing for enhanced use of tissue removal systems used for obtaining tissue samples from the body, including specifically, tissue from a potential lesion or suspicious mass within a female patient""s breast. Such information may also be used in conjunction with other targeted instruments such as guide wire placement devices and instruments for ablation, delivery, etc.
Yet another objective of the present invention is to provide an enhanced imaging/biopsy system for obtaining depth-related image information for diagnostic use and for otherwise yielding biopsy-related control and access advantages.
These objectives and additional advantages are met by various aspects of the present invention. In this regard, one aspect of the present invention provides for the combinative use of x-ray imaging and targeted ultrasound imaging. More particularly, this inventive aspect provides for the transmission of x-ray radiation through a selected body region-of-interest within a predetermined, three-dimensional frame of reference to obtain x-ray image data corresponding with one or more x-ray images. Additionally, an ultrasound signal is directed into a limited, selectively targeted portion of the x-rayed body region of interest to provide ultrasound image data corresponding with one or more ultrasound images of the targeted portion of the selected body region. The x-ray and ultrasound image data are acquired in spatial co-relation by utilizing x-ray imaging means and ultrasound imaging means each supportably positioned in known co-relation to the predetermined, three-dimensional frame of reference. This arrangement allows the x-ray and ultrasound image data to combinatively provide correlated, three-dimensional image data corresponding with the body region of interest. In turn, the spatially correlated information allows for an enhanced medical diagnosis of a given location of interest within the body region (e.g., potential lesion or suspicious mass in a breast application) and enhanced biopsy options in relation thereto.
In an additional aspect of the present invention, an ultrasound imaging means is provided that is advantageously positionable in direct contact with the body region of interest for optimal ultrasound image acquisition. More particularly, in breast imaging applications, opposing compression plates may be employed to immobilize a patient""s breast within the predetermined, three-dimensional frame of reference, wherein an opening is provided in one of the compression plates for selectively positioning an ultrasound imaging head (e.g., comprising a linear ultrasound transducer array) therethrough in contact with the patient""s breast for imaging. The ultrasound imaging means may be positioned below and on either side of a center axis of a patient support table, or alternatively, may be positioned below and in substantially coaxial relation to a patient support table.
In another aspect of the present invention, a locating means (e.g., an image data processor with display/user interface) is provided for using x-ray and ultrasound image data to identify a particular location of interest within the body region of interest; and a biopsy means is provided for obtaining a sample from the identified location of interest. In this regard, the biopsy means may include positioning means for selectively and supportably positioning an elongated puncture instrument or other tissue removal system relative to the predetermined, three-dimensional frame of reference, including for example positioning at a desired entry angle.
In a further aspect of the present invention, an ultrasound imaging means is provided that comprises a means for selectively positioning an elongated ultrasound imaging head in a known position relative to the predetermined, three-dimensional frame of reference, including angulation of the ultrasound imaging head relative to the predetermined frame of reference. In the latter regard, the imaging head may be angled to image a layer, or xe2x80x9cslice,xe2x80x9d of the body region of interest from a direction orthogonal to a direction from which an angled puncture instrument or other tissue-removal system may be advanced within such layer (i.e., the longitudinal axes of the imaging head and puncture instrument are substantially parallel). Such ultrasound imaging allows for processor simulation/display of a biopsy procedure using a tissue-removal system from a given biopsy position, as well as real-time imaging/control of a biopsy device as it is actually advanced into the body region of interest.
In an additional aspect of the present invention, an ultrasound imaging means is provided that comprises a positioning means for supportably and selectively positioning an ultrasound imaging probe in known spatial relation to the predetermined, three-dimensional frame of reference, while also and alternatively allowing the ultrasound imaging probe to be disengaged from the positioning means and manually manipulated in hand-held procedures. More particularly, the positioning means may comprise a holder means for selectively receiving an ultrasound imaging probe that is also adapted for hand-held use, wherein the probe may be selectively employed for hand-held manipulation or alternatively positioned within the holder means (e.g., via sliding and/or xe2x80x9csnap-inxe2x80x9d engagement). In the later regard, the positioning means may be employed to supportably position the ultrasound imaging probe in predetermined relation relative to the predetermined three-dimensional frame of reference to obtain depth information in a desired layer, or xe2x80x9cslicexe2x80x9d of the body region of interest. Further, the positioning means may comprise one or more drive means for providing at least partial automated positioning of the ultrasound imaging probe (e.g., for automated X and/or Y dimension positioning and/or for automated rotational positioning about a Z axis within an XY plane).
As indicated above, x-ray images may be employed to select a limited, or targeted, portion of the x-rayed body region of interest to be imaged utilizing the ultrasound signal. Such targeted ultrasound imaging avoids the acquisition, storage and processing of unneeded imaging data, and otherwise facilitates efficient use of medical personnel time, and otherwise advantageously accommodates direct contact with the body portion to be imaged. Further, where necessary, the provision of a hand-held ultrasound imaging option provides practitioners with added flexibility as may be desirable in certain applications.
According to a further aspect of the present invention, an ultrasound imaging apparatus is provided that has an improved imaging focal depth. It has been noted that a linear array of transducer elements may have a focal depth that is only a portion of the thickness of a patient""s immobilized breast. In this regard, in order to provide for more complete imaging for a range of patients, it is desirable to provide a greater focal depth. In particular, it would be desirable to provide a focal depth to accommodate a range of patients and procedures. A corresponding apparatus with improved focal depth includes a probe structure supporting a transducer array that includes at least a first set of transducer elements disposed a first distance from the signal interface surface of the probe structure and a second set of transducer elements disposed a second distance from the signal interface surface. The first and second sets of elements thereby provide a combined focal depth that is greater than the focal depth that would be provided by either of the transducer sets considered alone. In a preferred implementation, a transducer array includes 7 or more columns of array elements where each column is disposed a different distance from the signal interface surface of the probe structure. Such a structure provides for improved imaging for a range of patients.
In accordance with a still further aspect of the present invention, a display is provided proximate to the patient""s breast in order to facilitate real time monitoring of insertion of a medical instrument into the patient""s breast. The associated apparatus includes: an immobilizer for immobilizing the patient""s breast; a first graphical display for displaying one or more images of the patient""s breast so as to permit identification of an area of interest within the patient""s immobilized breast; a medical instrument operative for insertion to the identified area of interest within the patient""s breast; and a second graphical display, separate from the first graphical display and located proximate to the patient""s immobilized breast, for providing real time images of the patient""s compressed breast so that a user can monitor insertion of the medical instrument to the identified location of interest using the second graphical display located proximate to the patient""s immobilized breast. Preferably, the second graphical display can be translated and rotated to facilitate viewing during a medical procedure. In one embodiment, the patient is supported in a prone position on a table with the breast under examination protruding through an opening in the table and the second display is disposed beneath the table for convenient viewing. Real time images such as ultrasound images can be monitored on the second display during insertion of a medical instrument such as a biopsy needle for improved guidance and confidence regarding sampling of suspicious masses.
According with a still further aspect of the present invention, an improved graphical interface is provided for guiding a user through a medical procedure. The associated method includes the steps of: providing a mammographic medical device for use in performing a medical procedure on a patient""s breast; providing a display device having a graphical viewing area; providing a processor operative to drive the display device so as to display selected information in the viewing area; operating the display device using the processor to provide a first display whereby the user is presented with options corresponding to different operating modes of the medical device; operating the processor in response to an input regarding the operating mode to provide instructions for operating the medical device to obtain first and second images, where at least one of the images is an ultrasound image; operating the processor to display the images in a first portion of the graphical viewing area and provide graphical objects in a second portion of the viewing area for use in entering information related to the medical procedure; and using the first and second images to perform a medical procedure on the patient""s breast.
Preferably, one of the images is an x-ray image and the other image is an ultrasound image. In response to prompts provided via the display device, the user can identify a location of interest within the patient""s breast on each of the first and second images. The user may also enter certain image enhancement functions and enter additional information such as needle type using the display device. In one implementation, the processor is operative for displaying a projected penetration path of a medical instrument in superimposition on at least one of the images. The processor may further be operative for comparing an actual penetration path to the projected penetration path to identify any deviation therebetween and, if desired, to provide appropriate warnings. The graphical user interface system thereby provides enhanced functionality, provides simple to follow instructions for medical personnel and allows for close monitoring of a medical procedure for increased accuracy and confidence in the results.
Additional features and advantages of the present invention will become apparent upon consideration of the further description provided herein.